Logic 9 How to use automation to turn on/off by-pass on audio channel?

So...I send 2 channels (a kick and a snare) to the same bus and I put a plug as insert because I want to use automation to turn the plugs by-pass on and off...can't figure out how to do it without working on the single channel inserts...

I think I found out by myself! What I did is "create arrange track" typing control-click on the plug-in in the bus insert and it created a track in the arrangement window where I could be able to assign the by-pass in the automation window.
Let me know if there's any other way to do it! Thanks again!